Handbook of Information Security Management
(Publisher: CRC Press LLC)
Author(s): Hal Tipton and Micki Krause, Consulting Editors
ISBN: 0849399475
Publication Date: 01/01/98

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Detective Physical Controls

Detective physical controls warn protective services personnel that physical security measures are being violated. Examples of these controls include:

  • Motion detectors.
  • Smoke and fire detectors.
  • Closed-circuit television monitors.
  • Sensors and alarms.

Motion Detectors

In computing facilities that usually do not have people in them, motion detectors are useful for calling attention to potential intrusions. Motion detectors must be constantly monitored by guards.

Fire and Smoke Detectors

Fire and smoke detectors should be strategically located to provide early warning of a fire. All fire detection equipment should be tested periodically to ensure that it is in working condition.

Closed-Circuit Television Monitors

Closed-circuit televisions can be used to monitor the activities in computing areas where users or operators are frequently absent. This method helps detect individuals behaving suspiciously.

Sensors and Alarms

Sensors and alarms monitor the environment surrounding the equipment to ensure that air and cooling water temperatures remain within the levels specified by equipment design. If proper conditions are not maintained, the alarms summon operations and maintenance personnel to correct the situation before a business interruption occurs.

TECHNICAL CONTROLS

Technical security involves the use of safeguards incorporated in computer hardware, operations or applications software, communications hardware and software, and related devices. Technical controls are sometimes referred to as logical controls.

Preventive Technical Controls

Preventive technical controls are used to prevent unauthorized personnel or programs from gaining remote access to computing resources. Examples of these controls include:

  • Access control software.
  • Antivirus software.
  • Library control systems.
  • Passwords.
  • Smart cards.
  • Encryption.
  • Dial-up access control and callback systems.

Access Control Software

The purpose of access control software is to control sharing of data and programs between users. In many computer systems, access to data and programs is implemented by access control lists that designate which users are allowed access. Access control software provides the ability to control access to the system by establishing that only registered users with an authorized log-on ID and password can gain access to the computer system.

After access to the system has been granted, the next step is to control access to the data and programs residing in the system. The data or program owner can establish rules that designate who is authorized to use the data or program.

Antivirus Software

Viruses have reached epidemic proportions throughout the microcomputing world and can cause processing disruptions and loss of data as well as significant loss of productivity while cleanup is conducted. In addition, new viruses are emerging at an ever-increasing rate — currently about one every 48 hours. It is recommended that antivirus software be installed on all microcomputers to detect, identify, isolate, and eradicate viruses. This software must be updated frequently to help fight new viruses. In addition, to help ensure that viruses are intercepted as early as possible, antivirus software should be kept active on a system, not used intermittently at the discretion of users.

Library Control Systems

These systems require that all changes to production programs be implemented by library control personnel instead of the programmers who created the changes. This practice ensures separation of duties, which helps prevent unauthorized changes to production programs.

Passwords

Passwords are used to verify that the user of an ID is the owner of the ID. The ID-password combination is unique to each user and therefore provides a means of holding users accountable for their activity on the system.

Fixed passwords that are used for a defined period of time are often easy for hackers to compromise; therefore, great care must be exercised to ensure that these passwords do not appear in any dictionary. Fixed passwords are often used to control access to specific data bases. In this use, however, all persons who have authorized access to the data base use the same password; therefore, no accountability can be achieved.

Currently, dynamic or one-time passwords, which are different for each log-on, are preferred over fixed passwords. Dynamic passwords are created by a token that is programmed to generate passwords randomly.

Smart Cards

Smart cards are usually about the size of a credit card and contain a chip with logic functions and information that can be read at a remote terminal to identify a specific user’s privileges. Smart cards now carry prerecorded, usually encrypted access control information that is compared with data that the user provides (e.g., a personal ID number or biometric data) to verify authorization to access the computer or network.

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